Cover for drain tile joints



March 1964 w. L. BOENING COVER FOR DRAIN TILE JOINTS Filed Oct. 24, 1960 INVENTOR.

W/LFR'O 1.. BOI/V/IVG United States Patent 3,122,883 COVER FOR DRAIN TILE EGINTS Wilfred L. Boening, Boening Industries Inc, 19424 W. Eight lVfile Road, Detroit 19, Well. Filed 0st, 24, 1969, Ser. No. 64,489 3 Claims. (Cl. 61.11)

This invention relates to articles of manufacture intended for sub-soil use, and more particularly to a joint cover and cover assembly for use with underground drainage lines.

Underground drainage lines for use around building footings, septic tanks and for other drainage purposes are customarily constructed of a plurality of short cylindrical sections of clay soil pipe, commonly termed drain tiles. These tiles are laid end-to-end on a suitable bed of gravel or other water permeable earthen material, and instead of being joined together, the ends of adjoining tiles are spaced a short distance apart to permit passage of liquid from the sub-soil into the line, or vice versa, depending upon the particular application.

In order to prevent the earthen material located above the tiles from falling into the same through the tile joints, a cover made of tarpaper or molded plastic is ordinarily laid over the upper surfaces of adjacent ends of the tiles to span the gap therebetween. This leaves the lower half of the gap open to function as the liquid passage. Tile covers made of molded plastic are preferred for this purpose since such material is easily pre-formed into a semi-cylindrical shape with a rib portion on the inside thereof adapted to be inserted between the tiles to provide uniformly spaced tile lengths. However, joint covers of either type are subject to relatively rapid deterionation from the action of moisture, fungus and/or soil acids, and are ineffective against a major problem encountered with drainage lines of the above construction; namely, clogging caused by root growths entering the line at the joints.

One known solution to root clogging is to revert to covers which must be formed in place by wrapping a copper wire screen completely around the joint. The metallic copper in the screen gradually reacts with soil acids to produce copper sulfate which leaches into the soil surrounding the screen to form an effective chemical barrier against root growths in the vicinity of the tile joints. However, such screen covers involve additional time and expense both to install the cover and to space the tiles, and they tend to become clogged by soil particles.

Accordingly, it is an object of the present invention to provide an improved cover for drainage tile joints which is pre-formed of plastic and impregnated to withstand the aforesaid deleterious sub-soil conditions.

Another object is to provide a plastic tile cover assembly which is inexpensive to manufacture and install and which readily accommodates expansion of the tiles to prevent buckling of the line.

A further object is to provide an improved plastic cover-spacer assembly for tile joints which not only resists deterioration from the sub-soil conditions but also actively prevents root growths from clogging the joints without being subject to clogging by soil particles.

In the accompanying drawings:

FIG. 1 is a longitudinal sectional view taken on line 11 of FIG. 2 of a tile cover assembly provided in accordance with the invention positioned in the joint between the adjacent ends of two adjoining lengths of drainage tile;

FIG. 2 is a transverse sectional view of the same taken on line 22 of FIG. 1;

FIG. 3 is an exploded perspective view of the tile cover assembly;

FIG. 4 is a plm view of the tile cover positioned between the drain tiles, as in FIG. 1; and

FIG. 5 is an enlarged fragmentary view of a portion of FIG. 1.

Referring in more detail to the drawing, a two piece cover assembly of the invention is shown in FIG. 3 which includes a generally semi-cylindrical shell 11 and a metallic copper member or wire 12 shaped to co-operate therewith when installed between the adjacent ends of a pair of adjoining drain tiles 13' and 14. The tile cover assembly is shown in such position in the other figures of the drawing. The shell 11 is preferably made of a plastic composition and is pre-forrned by a suitable molding or extrusion process with a curvature generally corresponding to that of the outer circumference of the drain tiles 13 and 14. Shell 11 has an axial length which is sufiicient to provide substantial overlapping margins 11a and 11b which encircle the respective upper, outer surfaces of drain tiles 13 and 14 when installed to cover the upper half of the gap or joint 16 between the tiles. Hence, backfill which would otherwise tend to enter the open joint 16 by force of gravity is shielded therefrom by shell 11.

An integral, semi-annular rib portion 17 extends radially inward from the axial center of the inner surface of shell 11. The opposite sides 17a, 17b of rib portion 17 extend in mutually converging direction from the inner surface of shell 11 so that the rib forms a wedge to facilitate insertion of the shell between tiles 13 and 14. When shell 11 is fully inserted as in FIG. 1 the tiles are held spaced apart a distance equal to the axial dimension between sides 17a, 17b at the junctions thereof with shell 11.

The interior of rib portion 17 is provided with an annular bore extending longitudinally of the rib which reduces the weight of shell 11 and permits compression of the rib to accommodate axial expansion of drain tiles 13 and 14 as the moisture content thereof increases. A deformed position of rib portion 17 is illustrated by the dotted lines of FIG. 5. The bore 170 also provides a pair of openings at the ends of rib portion 17 which receive the particularly formed ends of the strand of wire 12. Each end of wire 12 has a portion 12a doubled back with respect to the main semi-circular portion of the strand and terminates with an axially extending portion 12b. Portion 12a forms a resilient insert which, when squeezed against the main portion of tie wire 12, is insertable with a close sliding fit in the end of bore 170 until the portion 12b engages the end face of rib 17. When released, the doubled ends of tie-wire 12 expand against the inner surfaces of bore 17c to hold wire 12 firmly in place. it is to be noted that wire 12 and rib :17 are preformed with substantially the same diameter corresponding to the median diameter of drain tiles 13, 14 so that when the cover assembly is inserted therebetween wire 12 is located substan tially in the axial center of the lower half of joint 16 and between the inner and outer surfaces of drain tiles 13, 14. As shown in FIG. 4, a double-ended arrow 18 or other suitable axial marking is provided on the outer surface of shell 11 at the center thereof to assist in aligning the shell over the upper half of joint 16. V

The tile cover assembly of the invention is impervious to the deleterious effects of sub-soil moisture and fungus growths, and prevents root from clogging the tile joints due to the structural and chemical organization of shell 11 with wire 12. Shell 11 is preferably made from a vinyl plastic composition which is fungus resistant and which, when constructed in the form described above, has proved to be effective against the damaging tendency of roots to grow into joint 16. One such composition proven suitable for this purpose is as follows:

The composition of the above formula contains .09% metallic solubilized copper, such as that sold under the trademark S-Quinolinolate by Ferro Chemical Company. The metallic copper is mixed with the plasticizer so as to form a thick paste prior to its incorporation with the remaining ingredients. The lead base stabilizer prevents the composition from'becoming too hard during extrusion of shell 11, while the calcium carbonate serves as a filler material.

The metallic member 12 is preferably pre-formed from a single strand l4-gauge hard copper wire which resists corrosion by subsoil water but which provides a body of copper which gradually reacts with soil acids to produce a continuous supply of copper sulfate around the lower half of the joints. The copper sulfate disperses around wire 12 and iseffective against root growths within a radius of about one inch therefrom. However, the single strand of wire permits substantially unobstructed passage of liquid through the joint, since the gap thereof usually ranges from A to /3 inches. g

It will now be apparent that a tile joint cover assembly made in accordance with the invention is extremely durable, and contributes materially to the life and operating efiiciency of the drainage line. The pre-formed tile cover assembly may be quickly assembled and inserted between adjoining draining tiles without tools and insures uniformly spaced tile lengths even when installed by unskilled labor. Moreover, the cover assembly of the invention effectively keeps root growths out of the drainage line itself Without preventing their growth in the drainage trench surrounding the line so that trees or other vegetation may obtain water without damaging the system.

I claim:

1. An anti-clogging water permeable joint construction for use at the open joints between underground drainage tiles, including in combination, a pair of drainage tiles arranged in end-to-end relation with their adjacent ends spaced apart, a shell made of a composition including polyvinyl chloride, a plasticizer and metallic copper as solubilized copper, said shell being pre-formed with a substantially semi-cylindrical shape conforming closely to the upper half of the outer circumference of the drainage tiles and having an axial length such that said shell overlaps the ends of adjoining tiles as well as spans the gap there-between to prevent backfill from clogging the joint, said shell having an integral rib portion extending inwardly from the axial center of the inner surface thereof with converging sides for wedging and uniformly spacing the adjoining tiles apart, said rib portion having an inner bore extending longitudinally thereof to permit resilient deformation thereof to accommodate axial expansion of 6 the tiles, and a strand of hard copper wire preformed with a curvature substantially equal to the median diameter of the tiles and having each end thereof doubled back so as to be insertable when squeezed into the respective ends of said bore and frictionally held therein when released, said strand of wire being suspended from said shell by said doubled back ends in said bore ends in the lower half of the open joint between the tiles to provide a source of metallic copper which reacts with soil acids to produce copper sulfate to inhibit root growth therein While permitting passage of liquids therethrough.

2. An anti-clogging water permeable joint construction for use at the open joints between underground drainage tiles, including in combination, a pair of drainage tiles arranged in end-to-end relation with their adjacent ends spaced apart, a shell pre-formed witha substantially semicylindrical shape conforming closely to the upper half of the outer circumference of the drainage tiles and having an axial length such that said shell overlaps the ends of adjoining tiles as well as spans the gap therebetween to prevent backfill from clogging the joint, said shell having I an integral rib portion extending inwardly from the axial center of the inner surface thereof with converging sides for wedging and uniformly spacing the adjoining tiles apart, said rib portion having an inner bore extending longitudinally thereof to permit resilient deformation thereof to accommodate axial expansion of the tiles, and

a strand of hard copper wire preformed with a curvature substantially equal to the median diameter of the tiles and having each end thereof doubled back so as tobe insertable when squeezed into the respective ends of said bore and frictionally held therein when released, said strand of wire being suspended from said shell by said doubled back ends in said bore ends in the lower half of the open joint between the tiles to provide a source of metallic copper which reacts with soil acidsto produce copper sulfateto inhibit root growth therein while permitting passage of liquids therethrough.

3. The combination set forth in claim 2 wherein said doubled back ends of said strand of wire comprises a return bend portion and a terminal portion bent from said return bend portion and projecting generally perpendicular to the strand of wire intermediate said ends thereof and adapted to abut the end of said rib portion to form a stop which limits insertion of said Wire in said bore ends to thereby position said wire in the gap between said tiles.

References Cited in the file of this patent UNITED STATES PATENTS 3,081,599 Roberg Mar; 19, 1963 OTHER REFERENCES Disinfection and Sterilization (McCulloch) 1945, page 266. 

1. AN ANTI-CLOGGING WATER PERMEABLE JOINT CONSTRUCTION FOR USE AT THE OPEN JOINTS BETWEEN UNDERGROUND DRAINAGE TILES, INCLUDING IN COMBINATION, A PAIR OF DRAINAGE TILES ARRANGED IN END-TO-END RELATION WITH THEIR ADJACENT ENDS SPACED APART, A SHELL MADE OF A COMPOSITION INCLUDING POLYVINYL CHLORIDE, A PLASTICIZER AND METALLIC COPPER AS SOLUBILIZED COPPER, SAID SHELL BEING PRE-FORMED WITH A SUBSTANTIALLY SEMI-CYLINDRICAL SHAPE CONFORMING CLOSELY TO THE UPPER HALF OF THE OUTER CIRCUMFERENCE OF THE DRAINAGE TILES AND HAVING AN AXIAL LENGTH SUCH THAT SAID SHELL OVERLAPS THE ENDS OF ADJOINING TILES AS WELL AS SPANS THE GAP THEREBETWEEN TO PREVENT BACKFILL FROM CLOGGING THE JOINT, SAID SHELL HAVING AN INTEGRAL RIB PORTION EXTENDING INWARDLY FROM THE AXIAL CENTER OF THE INNER SURFACE THEREOF WITH CONVERGING SIDES FOR WEDGING AND UNIFORMLY SPACING THE ADJOINING TILES APART, SAID RIB PORTION HAVING AN INNER BORE EXTENDING LONGITUDINALLY THEREOF TO PERMIT RESILIENT DEFORMATION THEREOF TO ACCOMODATE AXIAL EXPANSION OF THE TILES, AND A STRAND OF HARD COPPER WIRE PREFORMED WITH A CURVATURE SUBSTANTIALLY EQUAL TO THE MEDIAN DIAMETER OF THE TILES AND HAVING EACH END THEROF DOUBLED BACK SO AS TO BE INSERTABLE WHEN SQUEEZED INTO THE RESPECTIVE ENDS OF SAID BORE AND FRICTIONALLY HELD THEREIN WHEN RELEASED, SAID STRAND OF WIRE BEING SUSPENDED FROM SAID SHELL BY SAID DOUBLED BACK ENDS IN SAID BORE ENDS IN THE LOWER HALF OF THE OPEN JOINT BETWEEN THE TILES TO PROVIDE A SOURCE OF METALLIC COPPER WHICH REACTS WITH SOIL ACIDS TO PRODUCE COPPER SULFATE TO INHIBIT ROOT GROWTH THEREIN WHILE PERMITTING PASSAGE OF LIQUIDS THERETHROUGH. 